The aforementioned problem has earlier been observed, and various solutions have been proposed in an attempt to overcome the problem.
For example, there is described in SE-B-147.339 (Siemens-Reiniger-Werke) a method of eliminating oscillation of an X-ray apparatus by electro mechanical means. In the arrangement therein described there is used a support means which comprises at least two rigid members which can be adjusted relative to one another and which support against a part which is separate from the apparatus and which is stationary relative to the apparatus part to be supported. The stationary part may, for example, comprise the ceiling of a treatment room.
Such arrangements, which utilize a fixed support point externally of the X-ray stand, are normally particularly complicated and constitute a serious limitation to the extent to which the X-ray frame can be moved.
Consequently, such arrangements are unsuitable and have not met with wide use in modern X-ray stands.
Other types of arrangements are described in U.S. Pat. No. 4,287,424 (Tomita et al) which teaches a plurality of damping mechanisms in connection with tomography; U.S. Pat. No. 4,181,347 (Clark) which teaches vibration damping for mobile X-ray units; and U.S. Pat. No. 4,050,551 (Schmedemann et al) which teaches an arrangement for damping oscillations or vibrations in conjunction with counterweights.
None of these known arrangements provides a satisfactory solution to the problem of quickly damping effectively the natural oscillations of a pillar-stand carrying X-ray equipment.